Pinging on light throttle

[WhiteWhale]

Manual V6 S1 wagon pings under load. Occasionally runs super rich.

Car has approx 300k km on it.

Driven about 700km a week to & from work on open roads at 80-100kmh. The car starts 1st time each time.

Pings in all gears if I go to roll into the throttle once the car is warm. If I go wide open most times it decreases or stops but it’ll still ping now n then. Sometimes the car just randomly drives really well.

Occasional code 13 (O2 sensor related). No other codes but I’ve read that the ECUs aren’t the best at error codes anyway.

Known problem
At least one Welch plug is leaking, previous owner put stop leak in cooling system.

Tests
Ecu reset sometimes cures it.
Plug leads not leaky or cracked.
Checked vacuum hoses, sprayed (wasted!) carby cleaner everywhere and not one issue.
MAP and hoses good and clean.


New gear;
Crank position sensor
Knock sensor
Spark plugs
Air filter
Fuel filter

I’m guessing 6 months of 700km a day driving at 80-100 should have cleaned carbon off stuff.

Don’t know condition of injectors.

Any tips to fix this up?

I can’t stand hearing it knowing it does damage.

Mechanic went over it all with me as well and short of pulling fuel rail to check injectors doesn’t know what else to suggest.

 

[trel]

Fuel pump? What about the knock sensors themselves? Timing? You gotta check these things too if you haven't already.

 

[Immortality]

O2 sensor could be causing these problems and you say it happens once it warm which is when the ECU goes into closed loop mode and runs off the O2 sensor.

 

[WhiteWhale]

Fuel pump? What about the knock sensors themselves? Timing? You gotta check these things too if you haven't already.

Thanks…I could the pump and see if it’s in tank sieve/filter is blocked. Seems ok mostly, not too noisy, behaves on start up and shut down. I have wondered if the FPR is ‘stiff’ as I’m not giving extra fuel to small changes in vacuum. Mechanic reckon both are good and if they had probs the car would run super bad.

 

[WhiteWhale]

O2 sensor could be causing these problems and you say it happens once it warm which is when the ECU goes into closed loop mode and runs off the O2 sensor.

Hmmm short of looking up voltage values I don’t know how to test that. It’s in a super annoying place to access too. I do have a new one so maybe I should just put the bloody thing in.

 

[07GTS]

are u sure its pinging as the VN engine was quite rattley like a bag of bolts was within but can run fine for many hundreds of thousands of km

 

[WhiteWhale]

are u sure its pinging as the VN engine was quite rattley like a bag of bolts was within but can run fine for many hundreds of thousands of km

Pretty sure it’s pinging.

If I hold throttle position I can hear the pinging stop as the ecu pulls timing out. Other times, especially when warm, it’ll keep pinging away until I back off the throttle or change down a gear.

 

[07GTS]

Pretty sure it’s pinging.

If I hold throttle position I can hear the pinging stop as the ecu pulls timing out. Other times, especially when warm, it’ll keep pinging away until I back off the throttle or change down a gear.

if it does it when at a light to mid throttle and then goes away when u to wide open that dosnt make sense for knock, knock will get worse the more load is placed on it till its enough to stop the engine like a limiter, 02 data will show whats going on at the time a mechanic should be able to watch it happen, and if there is knock sensors then see if they are showing knock or not, also should be able to watch timing see what its doing, it can take a fair bit to make engines ping esp under light to mid loads and most of the time u wont even notice it happen and when it does it takes a chunk out not bit by bit and if it stays pinging it learns and keeps the timing out to prevent further damage

 

[WhiteWhale]

if it does it when at a light to mid throttle and then goes away when u to wide open that dosnt make sense for knock, knock will get worse the more load is placed on it till its enough to stop the engine like a limiter, 02 data will show whats going on at the time a mechanic should be able to watch it happen, and if there is knock sensors then see if they are showing knock or not, also should be able to watch timing see what its doing, it can take a fair bit to make engines ping esp under light to mid loads and most of the time u wont even notice it happen and when it does it takes a chunk out not bit by bit and if it stays pinging it learns and keeps the timing out to prevent further damage

Thanks for this, I’m going to sit n think on your reply.

I’d been thinking maybe it was leaning out and pinging because air/fuel mix was easily detonated under pressure. On WOT the mixture is more fuel rich so it goes off the spark plug not heat & pressure. Please feel free to set me right if my thinking is off. I’m not a mechanic, just keen, willing to learn and want to get it sorted.

I’ll put this new O2 sensor in, somehow. Hard to get at from above and impossible from below.

 

[07GTS]

Thanks for this, I’m going to sit n think on your reply.

I’d been thinking maybe it was leaning out and pinging because air/fuel mix was easily detonated under pressure. On WOT the mixture is more fuel rich so it goes off the spark plug bit heat & pressure. Please feel free to set me right if my thinking is off. I’m not a mechanic, just keen, willing to learn and want to get it sorted.

I’ll put this new O2 sensor in, somehow. Hard to get at from above and impossible from below.

leaning out under normal driving conditions to the point of knock or preignition would make driving very unpleasant kinda like if someone took 2-3 plugs out it would not be happy, also the fuel trims should be trying to keep fuel in line so they would have to be maxed out 20-30% trying to add in fuel before it would reach the limit and then start to lean out, anything like this if its lean using more throttle would make it much worse, if fueling cant keep up with little throttle then adding more throttle just instantly adds more air making the situation worse real quick to the point the engine will feel like its cutting out completely (not good to do) try the 02 sensor if its been a while could help,

02's work on a 0-1v scale 0v being lean and 1v being rich, normal driving when up to temp should see the 02's value shifting above and below the 0.45v constantly thats showing its operating properly, when u go full throttle the reading should be around the 0.80v or above showing its richer, if the full throttle shows under the 0.45 then ur way lean for full throttle